embarcadero and palo alto ave concepts v5 · ped/bike underpass. • fix traffic lights between...
TRANSCRIPT
Embarcadero and Palo Alto Ave Concepts
David Shen, Tony Carrasco, Jason MatlofV5 12‐10‐18
Embarcadero Ave
Why talk about Embarcadero?
• 1930s structure overdue for upgrade.• Alma on bridge necks down from 4 to 3 lanes.• Embarcadero underneath necks down from 4 to 3 lanes.
• Traffic flow between two arterials, Alma and Embarcadero, is not optimal
• Not enough protected access ramps to/from each road and in all directions.• Traffic flows through neighborhood streets to make transition
• Traffic lights at Town and Country and El Camino do not encourage good flow
Goals
• Upgrade/update old 1930s structure.• Reduce traffic flow in neighborhood streets.• Increase safety and access for pedestrians and cyclists.
• Preserve/enhance pedestrian and cyclist access under Alma with rebuild.• Improve Paly student pedestrian light with another option, ie. Ped/bike underpass.
• Fix traffic lights between Alma and El Camino.• Remove a light or two if possible.• Coordinate lights to improve traffic flow.
• Do all this without property takings• “Minimize eminent domain”
Concept Goals
• STIMULATE THINKING AND POSSIBILITIES • NOT ACTUAL SOLUTIONS TO BE DEBATED• NEED FURTHER DESIGN AND STUDY
• TREAT TRAFFIC SOLUTIONS IN PALO ALTO AS A SYSTEM• NOT AS INDIVIDUAL INTERSECTIONS
Concept 1: Josh Mello – Curve Embarcadero to the south, add exit loop onto Embarcadero West.
Exit loop
Orange= original path of Embarcadero
Traffic light
Traffic light
Concept 2: Josh Mello – Curve Embarcadero to the south, add left exit lane from Alma North onto Embarcadero West.
Left exit lane
Orange= original path of Embarcadero
Traffic light
Traffic light
Exit ramp from Kingsley to Embarcadero West
Orange= original path of Embarcadero
Traffic light
Traffic light
Concept 3: Exit ramp from Alma North onto Embarcadero West. Curve Embarcadero to south
Concept 4: Tony Carrasco – Create traffic circle between Alma and Embarcadero
Palo Alto Ave
Goals
• Maintain access from Alma to El Camino into Menlo Park.• Improve traffic flow
• Maintain pedestrian/cyclist access • Create separated ped/bike access path alongside roadway
• Protect historic bridge and El Palo Alto tree.• Do all this without property takings
• “Minimize eminent domain”
Concept Goals
• STIMULATE THINKING AND POSSIBILITIES • NOT ACTUAL SOLUTIONS TO BE DEBATED• NEED FURTHER DESIGN AND STUDY
• TREAT TRAFFIC SOLUTIONS IN PALO ALTO AS A SYSTEM• NOT AS INDIVIDUAL INTERSECTIONS
Concept 1: Shift new road to El Camino to the south, take over park area of El Camino Park. Add sloping down road alongside Alma to drop down to underpass. If 2% grade, slope down begins at Everett.
Adjacent drop down 2 lanes, approx. 2‐3% grade
2 lanes slope up to meet El Camino, approx. 2‐4% grade
Traffic light governs flow
Train tracks remain at same level
Concept 1a: Shift new road to El Camino to the south, take over park area of El Camino Park. Add sloping down road alongside Alma to drop down to underpass. If 5% grade, slope can start in/around Hawthorne.
Adjacent drop down 2 lanes, approx. 5% grade
2 lanes slope up to meet El Camino, approx. 5% grade
Traffic light governs flow
Train tracks remain at same level
Concept 2: Tony Carrasco – Create rail viaduct from Menlo Park through Palo Alto downtown, change path of train tracks around historic bridge
FINAL WORD
• AGAIN: CONCEPTS TO STIMULATE THINKING AND CREATIVITY• ADVOCATE FOR EMBARCADERO TO BE INSERTED INTO THE WORK PLAN NOW
• FURTHER WORK AND STUDY IS NEEDED
• ADVOCATE FOR MORE STUDY ON PALO ALTO AVE• GOALS:
• MAKE PALO ALTO OVERALL A BETTER ENVIRONMENT FOR CARS, BIKES, AND PEDESTRIANS
• PRESERVE *ALL* NEIGHBORHOODS’ INTEGRITY• DO IT ALL WITHOUT PROPERTY TAKINGS
APPENDIX
About Grade and Grade Standards
Grade Standards Impact Projects
Design standards govern steepness of roads and tracks
For bikes/peds, ADA requires max 5% grade (10 ft min clearance)
Roadways can go up to 8% grade (15 ft clearance)
Trains need a more gradual grade than cars, bikes/peds
Caltrain has a design standard of 1% grade with a possibility of going up to 2% grade with permission (not on chart!).
Based on what we know, 2% grade is possible (Caltrain standards, UP Contract)
Freight trains can go 2% and High Speed Rail can go 4-6% (all prefer flatter)
FACTORS
Roadways up t o 8% could d iscourage
act ive t ransportat ion
Design speed defines profi les –
safe sight d istance
Minimum vert ical clearances must be
achieved
RR max standard grade = 1%
ADA max grade = 5%
CONSTRAINT RADE (Design Criteria)
Graphic below presented by City of Palo Alto 9/16/17 Community Workshop #1
10/18/17 16
Megan Kanne
Downtown Neighborhoods & Palo Alto Rail Crossings
ProfessorvilleDowntown NorthUniversity South
Embarcadero Underpass
❖ Thank you to David, Jason, and Tony
❖ Interesting ideas worthy of study
Embarcadero Underpass
❖ Removed from the scope of work in June1
❖ Measure B funds can’t be used
❖ Limited resources are available, both with respect to funding and in manpower, to study additional alternatives at this time
1 See City Council Action Minutes June 19, 2018 https://www.cityofpaloalto.org/civicax/filebank/blobdload.aspx?t=83343.25&BlobID=65728
Traffic Study
❖ Comprehensive and multimodal
❖ Account for GUP/Stanford’s growth (3k new units)
❖ Make the raw traffic study data public
❖ Implement test closures of the Churchill Ave. and Palo Alto Ave. crossings, both separately and potentially together
“No Build” Options
❖ Include the “No Build” options in the options matrix
❖ Including a ped/bike tunnel or Homer-style underpass
❖ Determine the economic impact of “No Build” options
Process
❖ Improved outreach using City resources (email, Twitter, etc)
❖ Signage at the crossings themselves announcing the project to the public
❖ Take the time to gather data and feedback before decisions are made to close these vital east/west traffic arteries
Thanks!
Nadia Naik December 17th, 2018 Palo Alto City Council
Design Alternative for ONLY Meadow and Charleston
Presenter version 2018.09.01
[email protected] www.calhsr.com
Problem
l PA residents prefer an underground solution.
l Tunnels at stations are costly (high cost of burying station)
l Trench under Meadow and Charleston may be fatally flawed because of the creeks
l Hybrid and Viaduct options are not well liked
Goal of this concept: l Creative solution l Addresses community preference for underground solution l Increases design alternatives l Minimize costs and impacts
Design Challenges:
l Caltrain and Freight must maintain operations during construction
l Temporary “Passing Tracks” during construction are highly disruptive and expensive
l Underground utility relocation is complicated and costly
l Matadero, Barron and Adobe Creeks create obstacles to underground alternatives
l Freight trains can’t handle steeper grades and constrain design alternatives
l Diesel freight tunnels require extra ventilation that electric trains don’t need (>$).
3
Existing Opportunities?
l Only 3 freight trains per day in PA – all at night and don’t impact circulation
l Freight makes up less than 5% of operations on the corridor
l Without freight, we have more design flexibility
l Future Dumbarton Rail Corridor improvements could reduce or eliminate freight trains
l Future freight could be electrified
New Design Alternative:
A short, electric train only tunnel under Meadow and Charleston ONLY
with a single track of freight on the surface. Requires two twin bore tunnels (TBM)
We are NOT advocating this as a SOLUTION
Only that it be included as an ALTERNATIVE for further study
This is a NEW idea that developed based on the early issues identified by preliminary AECOM engineering – it was NOT part of
the original Master List of Alternatives 5
Electric train tunnel with 1 track of freight on surface
Single track Freight At-grade
Caltrain/HSR Tunnel
Alameda Trench Corridor (E. Compton Blvd and Alameda Street, Compton )
7
• NOTE: This shows a TRENCH – we are proposing TUNNEL
• Right of Way (ROW) is 100 feet (same as South Palo Alto)
• This ROW fits 4 tracks – PA would have 2 Caltrain (in tunnel) and one freight track (at grade)
• A simple curve is needed to separate the single freight track
• 3 tracks enter a trench in Alameda instead of a tunnel – but similar concept
Conceptual example
Considerations:
l Electric only tunnel can be >2% grade (design flexibility)
l Goes under creeks (avoiding potential fatal flaw)
l Tunnel goes under the utilities, reducing the cost.
l Can maintain Caltrain/Freight operations during construction
l Tunnels without a station are much cheaper
l Tunnels are faster to build. l Construction time is much shorter - less work window
issues and little to no road disruption.
Additional Considerations:
l Temporary passing tracks (shoo-fly tracks) only at tunnel portal entrance & exit vs entire right-of-way (saves money)
l With careful planning, TBM’s can be reused by other cities
l Some or all future freight may be re-routed over Dumbarton Rail route (currently being studied) leaving space for other land use options.
l Needs further study: Temporary space for the tunnel portal may be necessary and could require minimal commercial or residential eminent domain that could be returned to the commercial/housing stock on completion of the project
Source on TBM Reuse: https://www.herrenknecht.com/en/services/global-services/tbm-refurbishment.html
Comparative Project: Central Subway Tunnel in SF
l Built in 2014 in downtown San Francisco l Two twin bore machines (TBM) with 20.7 ft diameter for 1.7 miles l $234 million dollars (2014 dollars) l Built under an active BART line l Went through various soils: soft to thinly bedded siltstone, shale
and sandstone bedrock l Some soil even deemed “Potentially Gassy with Special
Conditions” by Cal/OSHA. l Navigated steep, turning alignment l Worked with low cover, urban utilities, and sensitive structures
requiring precautions to limit settlement impact and ensure the structures in downtown SF were safe.
10 Source: http://www.therobbinscompany.com/project-category/epb-tbm/
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View of Central Subway Twin Bore Tunnels
View of TBM Extraction Point
(above) View of Low Clearance under which Central Subway was built (and under ACTIVE BART line!)
Cost Comparisons
Hybrid Viaduct Trench Short Tunnel (no freight)
Estimated Cost 2018 $
$200M - $250M $400M - $500M $800M – 950M $400M - $550M*
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*CARRD estimated the Short Tunnel (No freight) alternative based on 2x price of similar 2014 SF Central Subway tunnel project in downtown SF Note: Costs could potentially be reduced further (next slide)
In 2014, Hatch Mott MacDonald estimated a trench under Meadow and Charleston (2% grade) would be $480 M. (Source: HMM Study 2014)
In 2018, AECOM estimated same trench would be $800 - $950 M – so costs have almost doubled since 2014. (Source: PA Community Meeting 11/14/18 slide 41)
Reducing Tunnel Cost further
l Reducing the tunnel diameter helps lower costs l 2014 – HSR White paper on Tunneling - significant cost
reductions by reducing max operating speeds assumptions from 220 to 200 mph thus reducing tunnel diameters from 29.5’ to 28’ ID (Inside Diameter).*
l AECOM studying City Wide tunnel with freight used 28’ Inside Diameter (assumes 200 mph)
l Tunnel diameter can be reduced since Caltrain/HSR will only operate max 125 mph on Peninsula
l Caltrain Electrification EIR shows that San Francisquito Creek bridge will have a maximum clearance of just 19ft. (See CARRD’s previous public comments re: Vertical Clearance assumptions)
13 *Source: California High-Speed Rail Program Whitepaper On Cost Reduction Strategies, 7/25/14
Direct Comparison of Tunnels Central Subway
No freight PA Short Tunnel
No freight
Length: 1.7 miles 1.6 miles Tunnel Diameter: 20.7 ft 28ft* (could be reduced)
Constraint: Built under active BART Under active Caltrain
Soil types: 5 various soil types including hazardous soils
Unknown but PA Tunnel White Paper says suitable for tunneling
Setting: Dense urban setting Empty suburban ROW Conditions: Steep, turning alignment with
vertical clearance issues Relatively flat, straight alignment with no vertical clearance issues
Special Circumstances:
Required special planning to support adjacent tall buildings
No buildings in ROW and no adjacent skyscrapers
14
Final Thoughts
l CARRD is NOT advocating that this is THE alternative – only that it be given further analysis
l Further preliminary analysis and study is needed and warranted for this alternative given strong community preference for underground solution.
l Too early to evaluate is this is the right solution
vs. other design alternatives – need more info
Appendix
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Palo Alto Right Of Way Widths
96 ft 85 ft 79 ft
*Approximate – not perfectly to scale. Not official diagram.